Polyvinyl-polyoxyalkylene block copolymers

Abstract

A mixed block copolymer of the A-B type is prepared. The A block of the block copolymer is formed by the polymerization of compounds having vinyl groups and the B block of which is a polyoxyalkylene block, obtainable by polymerizing, first of all, monomers having vinyl groups at temperatures of 60° to 150° C. by a free radical mechanism in the presence of sufficient amounts of an initiator and an amount, which corresponds to the desired chain length, of a chain-length regulator, which carries, aside from a mercapto group, a further functional group having at least one active hydrogen and adding alkylene oxide, optionally in the presence of a known addition reaction catalyst, in an addition reaction at 20° to 180° C. onto the polymer so modified, until the desired molecular weight of block B is reached.

I claim: 
     
       1. A process of making a mixed block copolymer of the A-B type, wherein block A is formed by polymerization of compounds having vinyl groups and wherein block B is a polyoxyalkylene block, comprising the steps of polymerizing monomers having vinyl groups in presence of sufficient amount of an initiator and a chain-length regulator which, in addition to a mercapto group, comprises a functional group having at least one active hydrogen, said polymerization being carried out at a temperature of about between 60° C. to 150° C. by a free radical mechanism to obtain a modified polymer; and subjecting the said modified polymer to an addition reaction with an alkylene oxide at a temperature of about between 20° to 180° C., said addition reaction being carried out optionally in the presence of an addition inducing catalyst until the desired molecular weight of block B is reached. 
     
     
       2. The process of claim 1, further comprising the steps of forming block A by a free radical polymerization of vinyl compounds having vinyl groups in the presence of at least one of a) solvent, and b) excess amount of the monomer, excess monomeric vinyl compounds and any solvent present being at least partially removed from the polymer obtained after the synthesis of block A. 
     
     
       3. The process of claim 1 or 2, further comprising that block A is formed by the polymerization of at least one of the compounds selected from the group comprising styrene and alkylstyrene. 
     
     
       4. The process of claim 1, further comprising polymerizing the monomers having vinyl groups in the presence of a chain-length regulator having at least one of the functional groups selected from the group consisting of hydroxyl, carboxyl and monoalkyl-substituted amino group aside from a mercapto group. 
     
     
       5. The process of claim 1, further comprising carrying out the polymerization in the presence of 1-mercapto-2-ethanol as chain-length regulator. 
     
     
       6. The process of claim 1, further comprising that block B is formed from at least one of the group consisting of oxyethylene, oxypropylene and oxybutylene units in block arrangement or in statistical distribution.